// Use this for initialization
public static void Main(String[] args)
{
// 83 is the base size (in bytes) of a serialized RDTPacket object
byte[] receivedData = new byte[Sender.MSS + 83];
int waitingFor = 0;
List <RDTPacket> received = new List <RDTPacket>();
bool end = false;
//
UdpClient fromSender = new UdpClient(new IPEndPoint(IPAddress.Parse("192.168.1.15"), 8080));
while (!end)
{
Console.WriteLine("Waiting for packet");
// Receive packet
IPEndPoint receivedPacket = new IPEndPoint(IPAddress.Parse("192.168.1.15"), 9876);
byte [] bytes = fromSender.Receive(ref receivedPacket);
// Unserialize to a RDTPacket object
RDTPacket packet = (RDTPacket)BinaryFormat.Deserialize(bytes);
Console.WriteLine("Packet with sequence number " + packet.getSeq() + " received (last: " + packet.isLast() + " )");
if (packet.getSeq() == waitingFor && packet.isLast())
{
waitingFor++;
received.Add(packet);
Console.WriteLine("Last packet received");
end = true;
}
else if (packet.getSeq() == waitingFor)
{
waitingFor++;
received.Add(packet);
Console.WriteLine("Packed stored in buffer");
}
else
{
Console.WriteLine("Packet discarded (not in order)");
}
// Create an RDTAck object
RDTAck ackObject = new RDTAck(packet.getSeq());
// Serialize
byte[] ackBytes = BinaryFormat.Serialize(ackObject);
IPEndPoint ackPacket = new IPEndPoint(IPAddress.Parse("192.168.1.15"), 9876);
// Send with some probability of loss
Random rand = new Random();
if (rand.Next(2, 3) > PROBABILITY)
{
fromSender.Send(ackBytes, ackBytes.Length, ackPacket);
}
else
{
Console.WriteLine("[X] Lost ack with sequence number " + ackObject.getPacket());
}
Console.WriteLine("Sending ACK to seq " + packet.getSeq() + " with " + ackBytes.Length + " bytes");
}
Console.ReadKey();
}
// Use this for initialization
public static void Main(String[] args)
{
int lastSent = 0;
int waitingForAck = 0;
byte[] fileBytes = System.Text.Encoding.Default.GetBytes("ABCDEFGHIJKLMNOPQRSTUVXZ");
Console.WriteLine("Data size: " + fileBytes.Length + " bytes");
int lastSeq = (int)Math.Ceiling((double)fileBytes.Length / MSS) - 1;// lastSent 从 0 开始 标记，这里要减去 1
Console.WriteLine("Number of packets to send: " + lastSeq);
string HostName = Dns.GetHostName(); //得到主机名
IPHostEntry IpEntry = Dns.GetHostEntry(HostName);
IPAddress receiverAddress = null;
for (int i = 0; i < IpEntry.AddressList.Length; i++)
{
//从IP地址列表中筛选出IPv4类型的IP地址
//AddressFamily.InterNetwork表示此IP为IPv4,
//AddressFamily.InterNetworkV6表示此地址为IPv6类型
if (IpEntry.AddressList[i].AddressFamily == AddressFamily.InterNetwork)
{
receiverAddress = IpEntry.AddressList[i];
break;
}
}
UdpClient toReceiver = new UdpClient(9876, AddressFamily.InterNetwork);
List <RDTPacket> sent = new List <RDTPacket>();
while (true)
{
// Sending loop
while (lastSent - waitingForAck < WINDOW_SIZE && lastSent < lastSeq)
{
// Array to store part of the bytes to send
byte[] filePacketBytes = new byte[MSS];
// Copy segment of data bytes to array
Array.Copy(fileBytes, lastSent * MSS, filePacketBytes, 0, MSS);
// Create RDTPacket object
RDTPacket rdtPacketObject = new RDTPacket(lastSent, filePacketBytes, (lastSent == lastSeq - 1) ? true : false);
// Serialize the RDTPacket object
byte[] sendData = BinaryFormat.Serialize(rdtPacketObject);
Console.WriteLine("Sending packet with sequence number " + lastSent + " and size " + sendData.Length + " bytes");
// Add packet to the sent list
sent.Add(rdtPacketObject);
// Send with some probability of loss
Random rand = new Random();
int num = rand.Next(0, 2);
if (num > PROBABILITY)
{
IPEndPoint IPPoint = new IPEndPoint(receiverAddress, 8080);
toReceiver.Send(sendData, sendData.Length, IPPoint);
}
else
{
Console.WriteLine("[X] Lost packet with sequence number " + lastSent);
}
// Increase the last sent
lastSent++;
} // End of sending while
// Byte array for the ACK sent by the receiver
byte[] ackBytes = new byte[40];
// Creating packet for the ACK
IPEndPoint ack = new IPEndPoint(IPAddress.Any, 0);
try
{
// If an ACK was not received in the time specified (continues on the catch clausule)
toReceiver.Client.ReceiveTimeout = TIMER;
// Receive the packet
byte[] bytes = toReceiver.Receive(ref ack);
// Unserialize the RDTAck object
RDTAck ackObject = (RDTAck)BinaryFormat.Deserialize(bytes);
Console.WriteLine("Received ACK for " + ackObject.getPacket());
// If this ack is for the last packet, stop the sender (Note: gbn has a cumulative acking)
if (ackObject.getPacket() == lastSeq)
{
break;
//return;
}
waitingForAck = Math.Max(waitingForAck, ackObject.getPacket());
}
catch (SocketException e)
{
// then send all the sent but non-acked packets
for (int i = waitingForAck; i < lastSent; i++)
{
// Serialize the RDTPacket object
byte[] sendData = BinaryFormat.Serialize(sent[i]);
// Create the packet
IPEndPoint packet = new IPEndPoint(receiverAddress, 8080);
// Send with some probability
Random rand = new Random();
if (rand.Next(2, 5) > PROBABILITY)
{
toReceiver.Send(sendData, sendData.Length, packet);
}
else
{
Console.WriteLine("[X_Resending] Lost packet with sequence number " + sent[i].getSeq());
}
Console.WriteLine("REsending packet with sequence number " + sent[i].getSeq() + " and size " + sendData.Length + " bytes");
}
}
}
Console.ReadKey();
}
